xref: /linux/arch/x86/Kconfig (revision 4590d98f5a4f466d17e5c81d7c9fc796da9a8cee)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
351032c0baSSam Ravnborg
36518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
37518049d9SSteven Rostedt (VMware)	def_bool y
38518049d9SSteven Rostedt (VMware)	depends on X86_32
39518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
40518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
41518049d9SSteven Rostedt (VMware)	help
42518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
43518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
44518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
45518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
46518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
47d94e0685SIngo Molnar#
48d94e0685SIngo Molnar# Arch settings
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
51d94e0685SIngo Molnar#   ported to 32-bit as well. )
52d94e0685SIngo Molnar#
538d5fffb9SSam Ravnborgconfig X86
543c2362e6SHarvey Harrison	def_bool y
55c763ea26SIngo Molnar	#
56c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
57c763ea26SIngo Molnar	#
586471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
596e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
60942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
612a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
64399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
6521266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
66b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
676471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
69316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
706974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
71957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
720f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
730c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7410bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
750ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
76c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7717596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
783010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
790aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
80ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
81d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
82d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
83ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
84ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
85ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8625c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
87c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
887e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
896471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
906471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
9177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
925e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
933599fe12SThomas Gleixner	select ARCH_STACKWALK
942c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
956471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
965d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
976471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
9814df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
996471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
1006471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1016471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1022ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
103ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
10481c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
105c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
1063876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
10759612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
10838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10910916706SShile Zhang	select BUILDTIME_TABLE_SORT
1106471b825SIngo Molnar	select CLKEVT_I8253
1116471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1126471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1136471b825SIngo Molnar	select DCACHE_WORD_ACCESS
11445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
11545471cd9SLinus Torvalds	select EDAC_SUPPORT
1166471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1176471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1186471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1196471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
12061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1216471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
12227d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1236471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1246471b825SIngo Molnar	select GENERIC_IOMAP
125c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1260fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
127ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1286471b825SIngo Molnar	select GENERIC_IRQ_PROBE
129c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1306471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1316471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1322ae27137SSteven Price	select GENERIC_PTDUMP
1336471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1346471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1356471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1366471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1377ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
138550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13939656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
14017e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1417edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1426471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1436471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1446471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1456471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1466471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1476471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
148b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
149d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1500609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1516471b825SIngo Molnar	select HAVE_ARCH_KGDB
1529e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1539e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1541b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
155271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1566471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
157f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
158afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1596471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1606471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
161a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
162b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
163e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
164c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1652ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1666471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1676471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1686471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
169d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1706471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1716471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1729c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
173677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
17406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
17502a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
176562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
17703f5781bSWang YanQing	select HAVE_EBPF_JIT
17858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1796630a8e5SChristoph Hellwig	select HAVE_EISA
1805f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
18167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
182644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1836471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1846471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1856471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1866b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1870067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1886471b825SIngo Molnar	select HAVE_IDE
1896471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1906471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1916471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1926471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1936471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1946471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1956471b825SIngo Molnar	select HAVE_KERNEL_LZO
1966471b825SIngo Molnar	select HAVE_KERNEL_XZ
197fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
1986471b825SIngo Molnar	select HAVE_KPROBES
1996471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
200540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2016471b825SIngo Molnar	select HAVE_KRETPROBES
2026471b825SIngo Molnar	select HAVE_KVM
2036471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2040102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
205ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2069f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
207be37c98dSKalesh Singh	select HAVE_MOVE_PUD
20842a0bb3fSPetr Mladek	select HAVE_NMI
2096471b825SIngo Molnar	select HAVE_OPROFILE
2106471b825SIngo Molnar	select HAVE_OPTPROBES
2116471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2126471b825SIngo Molnar	select HAVE_PERF_EVENTS
213c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
21492e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
215eb01d42aSChristoph Hellwig	select HAVE_PCI
216c5e63197SJiri Olsa	select HAVE_PERF_REGS
217c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
218ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
21900998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2206471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2216415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2223c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
223d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
224c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
225e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2261e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
227d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2286471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2296471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2307c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2317ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
23205736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
233c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
23486596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2352eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
236625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2376471b825SIngo Molnar	select PERF_EVENTS
2383195ef59SPrarit Bhargava	select RTC_LIB
239d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2406471b825SIngo Molnar	select SPARSE_IRQ
24183fe27eaSPranith Kumar	select SRCU
2421e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2436471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
24415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2456471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2466471b825SIngo Molnar	select VIRT_TO_BUS
2473b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2486471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2490c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2509e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2517d8330a5SBalbir Singh
252ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2533120e25eSJan Beulich	def_bool y
2543120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
255ba7e4d13SIngo Molnar
25651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
25751b26adaSLinus Torvalds	string
25851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
25951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
26051b26adaSLinus Torvalds
2618d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2623c2362e6SHarvey Harrison	def_bool y
2638d5fffb9SSam Ravnborg
2648d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2653c2362e6SHarvey Harrison	def_bool y
2668d5fffb9SSam Ravnborg
2678d5fffb9SSam Ravnborgconfig MMU
2683c2362e6SHarvey Harrison	def_bool y
2698d5fffb9SSam Ravnborg
2709e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2719e08f57dSDaniel Cashman	default 28 if 64BIT
2729e08f57dSDaniel Cashman	default 8
2739e08f57dSDaniel Cashman
2749e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2759e08f57dSDaniel Cashman	default 32 if 64BIT
2769e08f57dSDaniel Cashman	default 16
2779e08f57dSDaniel Cashman
2789e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2799e08f57dSDaniel Cashman	default 8
2809e08f57dSDaniel Cashman
2819e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2829e08f57dSDaniel Cashman	default 16
2839e08f57dSDaniel Cashman
2848d5fffb9SSam Ravnborgconfig SBUS
2858d5fffb9SSam Ravnborg	bool
2868d5fffb9SSam Ravnborg
2878d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2883120e25eSJan Beulich	def_bool y
2893120e25eSJan Beulich	depends on ISA_DMA_API
2908d5fffb9SSam Ravnborg
2918d5fffb9SSam Ravnborgconfig GENERIC_BUG
2923c2362e6SHarvey Harrison	def_bool y
2938d5fffb9SSam Ravnborg	depends on BUG
294b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
295b93a531eSJan Beulich
296b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
297b93a531eSJan Beulich	bool
2988d5fffb9SSam Ravnborg
2998d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3003120e25eSJan Beulich	def_bool y
3013120e25eSJan Beulich	depends on ISA_DMA_API
3028d5fffb9SSam Ravnborg
3031032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3041032c0baSSam Ravnborg	def_bool y
3051032c0baSSam Ravnborg
3069a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3079a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3088d5fffb9SSam Ravnborg
3091b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
3101b27d05bSPekka Enberg	def_bool y
3111b27d05bSPekka Enberg
312316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
313316d097cSDave Hansen	def_bool y
314316d097cSDave Hansen
315dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
31689c9c4c5SBrian Gerst	def_bool y
317b32ef636Stravis@sgi.com
31808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
31908fc4580STejun Heo	def_bool y
32008fc4580STejun Heo
32108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
32211124411STejun Heo	def_bool y
32311124411STejun Heo
324801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
325801e4062SJohannes Berg	def_bool y
326801e4062SJohannes Berg
327f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
328f4cb5700SJohannes Berg	def_bool y
329f4cb5700SJohannes Berg
33053313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
33153313b2cSSteve Capper	def_bool y
33253313b2cSSteve Capper
3338d5fffb9SSam Ravnborgconfig ZONE_DMA32
334e0fd24a3SJan Beulich	def_bool y if X86_64
3358d5fffb9SSam Ravnborg
3368d5fffb9SSam Ravnborgconfig AUDIT_ARCH
337e0fd24a3SJan Beulich	def_bool y if X86_64
3388d5fffb9SSam Ravnborg
339d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
340d6f2d75aSAndrey Ryabinin	hex
341d6f2d75aSAndrey Ryabinin	depends on KASAN
342d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
343d6f2d75aSAndrey Ryabinin
34469575d38SShane Wangconfig HAVE_INTEL_TXT
34569575d38SShane Wang	def_bool y
3466ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
34769575d38SShane Wang
3486b0c3d44SSam Ravnborgconfig X86_32_SMP
3496b0c3d44SSam Ravnborg	def_bool y
3506b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3516b0c3d44SSam Ravnborg
3526b0c3d44SSam Ravnborgconfig X86_64_SMP
3536b0c3d44SSam Ravnborg	def_bool y
3546b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3556b0c3d44SSam Ravnborg
356ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
357ccbeed3aSTejun Heo	def_bool y
3588458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
359ccbeed3aSTejun Heo
3602b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3612b144498SSrikar Dronamraju	def_bool y
3622b144498SSrikar Dronamraju
363d20642f0SRob Herringconfig FIX_EARLYCON_MEM
364d20642f0SRob Herring	def_bool y
365d20642f0SRob Herring
36694d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
36794d49eb3SKirill A. Shutemov	bool
36894d49eb3SKirill A. Shutemov
36998233368SKirill A. Shutemovconfig PGTABLE_LEVELS
37098233368SKirill A. Shutemov	int
37177ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
37298233368SKirill A. Shutemov	default 4 if X86_64
37398233368SKirill A. Shutemov	default 3 if X86_PAE
37498233368SKirill A. Shutemov	default 2
37598233368SKirill A. Shutemov
3762a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3772a61f474SMasahiro Yamada	bool
3782a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3792a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3802a61f474SMasahiro Yamada	help
3812a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3822a61f474SMasahiro Yamada	   the compiler produces broken code.
3832a61f474SMasahiro Yamada
384506f1d07SSam Ravnborgmenu "Processor type and features"
385506f1d07SSam Ravnborg
3865ee71535SRandy Dunlapconfig ZONE_DMA
3875ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3885ee71535SRandy Dunlap	default y
3895ee71535SRandy Dunlap	help
3905ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3915ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3925ee71535SRandy Dunlap	  Disable if no such devices will be used.
3935ee71535SRandy Dunlap
3945ee71535SRandy Dunlap	  If unsure, say Y.
3955ee71535SRandy Dunlap
396506f1d07SSam Ravnborgconfig SMP
397506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
398a7f7f624SMasahiro Yamada	help
399506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4004a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4014a474157SRobert Graffham	  than one CPU, say Y.
402506f1d07SSam Ravnborg
4034a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
404506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
405506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4064a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
407506f1d07SSam Ravnborg	  will run faster if you say N here.
408506f1d07SSam Ravnborg
409506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
410506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
411506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
412506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
413506f1d07SSam Ravnborg
414506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
415506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
416506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
417506f1d07SSam Ravnborg
418cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4194f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
420506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
421506f1d07SSam Ravnborg
422506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
423506f1d07SSam Ravnborg
4249def39beSJosh Triplettconfig X86_FEATURE_NAMES
4259def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4269def39beSJosh Triplett	default y
427a7f7f624SMasahiro Yamada	help
4289def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4299def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4309def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4319def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4329def39beSJosh Triplett
4339def39beSJosh Triplett	  If in doubt, say Y.
4349def39beSJosh Triplett
43506cd9a7dSYinghai Luconfig X86_X2APIC
43606cd9a7dSYinghai Lu	bool "Support x2apic"
43719e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
438a7f7f624SMasahiro Yamada	help
43906cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44006cd9a7dSYinghai Lu
44106cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44206cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44306cd9a7dSYinghai Lu
44406cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44506cd9a7dSYinghai Lu
4466695c85bSYinghai Luconfig X86_MPPARSE
447*4590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4487a527688SJan Beulich	default y
4495ab74722SIngo Molnar	depends on X86_LOCAL_APIC
450a7f7f624SMasahiro Yamada	help
4516695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4526695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4536695c85bSYinghai Lu
454ddd70cf9SJun Nakajimaconfig GOLDFISH
455ddd70cf9SJun Nakajima	def_bool y
456ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
457ddd70cf9SJun Nakajima
45876b04384SDavid Woodhouseconfig RETPOLINE
45976b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46076b04384SDavid Woodhouse	default y
46176b04384SDavid Woodhouse	help
46276b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46376b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46476b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46576b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46676b04384SDavid Woodhouse
467e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
468e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4696fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47059fe5a77SThomas Gleixner	select KERNFS
471e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47278e99b4aSFenghua Yu	help
473e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4746fe07ce3SBabu Moger
4756fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4766fe07ce3SBabu Moger	  usage by the CPU.
4776fe07ce3SBabu Moger
4786fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4796fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4806fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4816fe07ce3SBabu Moger
4826fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4836fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4846fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48578e99b4aSFenghua Yu
48678e99b4aSFenghua Yu	  Say N if unsure.
48778e99b4aSFenghua Yu
4888425091fSRavikiran G Thirumalaiif X86_32
489a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
490a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
491a0d0bb4dSRandy Dunlap	depends on SMP
492a7f7f624SMasahiro Yamada	help
493e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
494a0d0bb4dSRandy Dunlap
495c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
496c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
497c5c606d9SRavikiran G Thirumalai	default y
498a7f7f624SMasahiro Yamada	help
49906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50106ac8346SIngo Molnar	  systems out there.)
50206ac8346SIngo Molnar
5038425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5048425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
505cb7b8023SBen Hutchings		Goldfish (Android emulator)
5068425091fSRavikiran G Thirumalai		AMD Elan
5078425091fSRavikiran G Thirumalai		RDC R-321x SoC
5088425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
50983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5103f4110a4SThomas Gleixner		Moorestown MID devices
51106ac8346SIngo Molnar
51206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5148425091fSRavikiran G Thirumalaiendif
51506ac8346SIngo Molnar
5168425091fSRavikiran G Thirumalaiif X86_64
5178425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5188425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5198425091fSRavikiran G Thirumalai	default y
520a7f7f624SMasahiro Yamada	help
5218425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5228425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5238425091fSRavikiran G Thirumalai	  systems out there.)
5248425091fSRavikiran G Thirumalai
5258425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5268425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52744b111b5SSteffen Persvold		Numascale NumaChip
5288425091fSRavikiran G Thirumalai		ScaleMP vSMP
5298425091fSRavikiran G Thirumalai		SGI Ultraviolet
5308425091fSRavikiran G Thirumalai
5318425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5328425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5338425091fSRavikiran G Thirumalaiendif
534c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
535c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53644b111b5SSteffen Persvoldconfig X86_NUMACHIP
53744b111b5SSteffen Persvold	bool "Numascale NumaChip"
53844b111b5SSteffen Persvold	depends on X86_64
53944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54044b111b5SSteffen Persvold	depends on NUMA
54144b111b5SSteffen Persvold	depends on SMP
54244b111b5SSteffen Persvold	depends on X86_X2APIC
543f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
544a7f7f624SMasahiro Yamada	help
54544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54644b111b5SSteffen Persvold	  enable more than ~168 cores.
54744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
54803b48632SNick Piggin
5496a48565eSIngo Molnarconfig X86_VSMP
550c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5516276a074SBorislav Petkov	select HYPERVISOR_GUEST
5526a48565eSIngo Molnar	select PARAVIRT
5536a48565eSIngo Molnar	depends on X86_64 && PCI
554c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
555ead91d4bSShai Fultheim	depends on SMP
556a7f7f624SMasahiro Yamada	help
5576a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5586a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5596a48565eSIngo Molnar	  if you have one of these machines.
5606a48565eSIngo Molnar
561c5c606d9SRavikiran G Thirumalaiconfig X86_UV
562c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
563c5c606d9SRavikiran G Thirumalai	depends on X86_64
564c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56554c28d29SJack Steiner	depends on NUMA
5661ecb4ae5SAndrew Morton	depends on EFI
5679d6c26e7SSuresh Siddha	depends on X86_X2APIC
5681222e564SIngo Molnar	depends on PCI
569a7f7f624SMasahiro Yamada	help
570c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
571c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
572c5c606d9SRavikiran G Thirumalai
573c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
574c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
575506f1d07SSam Ravnborg
576ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
577ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
578cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
579a7f7f624SMasahiro Yamada	help
580ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
581ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
582ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
583ddd70cf9SJun Nakajima
584c751e17bSThomas Gleixnerconfig X86_INTEL_CE
585c751e17bSThomas Gleixner	bool "CE4100 TV platform"
586c751e17bSThomas Gleixner	depends on PCI
587c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5886084a6e2SJiang Liu	depends on X86_IO_APIC
589c751e17bSThomas Gleixner	depends on X86_32
590c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
592da6b737bSSebastian Andrzej Siewior	select OF
593da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
594a7f7f624SMasahiro Yamada	help
595c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
596c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
597c751e17bSThomas Gleixner	  boxes and media devices.
598c751e17bSThomas Gleixner
5994cb9b00fSDavid Cohenconfig X86_INTEL_MID
60043605ef1SAlan Cox	bool "Intel MID platform support"
60143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
602edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6031ea7c673SAlan Cox	depends on PCI
6043fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6051ea7c673SAlan Cox	depends on X86_IO_APIC
6064cb9b00fSDavid Cohen	select I2C
6077c9c3a1eSAlan Cox	select DW_APB_TIMER
6081ea7c673SAlan Cox	select APB_TIMER
60954b34aa0SMika Westerberg	select INTEL_SCU_PCI
61015a713dfSMika Westerberg	select MFD_INTEL_MSIC
611a7f7f624SMasahiro Yamada	help
6124cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6134cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6144cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6151ea7c673SAlan Cox
6164cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6174cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
61843605ef1SAlan Cox
6198bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6208bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6218bbc2a13SBryan O'Donoghue	depends on X86_32
6228bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6238bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6248bbc2a13SBryan O'Donoghue	depends on X86_TSC
6258bbc2a13SBryan O'Donoghue	depends on PCI
6268bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6278bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6288bbc2a13SBryan O'Donoghue	select IOSF_MBI
6298bbc2a13SBryan O'Donoghue	select INTEL_IMR
6309ab6eb51SAndy Shevchenko	select COMMON_CLK
631a7f7f624SMasahiro Yamada	help
6328bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6338bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6348bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6358bbc2a13SBryan O'Donoghue
6363d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6373d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6385962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6393d48aab1SMika Westerberg	select COMMON_CLK
6400f531431SMathias Nyman	select PINCTRL
641eebb3e8dSAndy Shevchenko	select IOSF_MBI
642a7f7f624SMasahiro Yamada	help
6433d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6443d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6450f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6460f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6473d48aab1SMika Westerberg
64892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
64992082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65092082a88SKen Xue	depends on ACPI
65192082a88SKen Xue	select COMMON_CLK
65292082a88SKen Xue	select PINCTRL
653a7f7f624SMasahiro Yamada	help
65492082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65592082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65692082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65792082a88SKen Xue	  implemented under PINCTRL subsystem.
65892082a88SKen Xue
659ced3ce76SDavid E. Boxconfig IOSF_MBI
660ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
661ced3ce76SDavid E. Box	depends on PCI
662a7f7f624SMasahiro Yamada	help
663ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
664ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
665ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
666ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
667ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
668ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
669ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
670ced3ce76SDavid E. Box	   - BayTrail
671ced3ce76SDavid E. Box	   - Braswell
672ced3ce76SDavid E. Box	   - Quark
673ced3ce76SDavid E. Box
674ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
675ced3ce76SDavid E. Box
676ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
677ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
678ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
679a7f7f624SMasahiro Yamada	help
680ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
681ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
682ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
683ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
684ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
685ed2226bdSDavid E. Box	  device they want to access.
686ed2226bdSDavid E. Box
687ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
688ed2226bdSDavid E. Box
689c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
690c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
691506f1d07SSam Ravnborg	depends on X86_32
692c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
693c5c606d9SRavikiran G Thirumalai	select M486
694c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
695a7f7f624SMasahiro Yamada	help
696c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
697c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
698c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
699c5c606d9SRavikiran G Thirumalai
700e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7019c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7029c398017SIngo Molnar	depends on X86_32 && SMP
703c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
704a7f7f624SMasahiro Yamada	help
705b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
706b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
707b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
708b5660ba7SH. Peter Anvin	  one and will fallback to default.
709d49c4288SYinghai Lu
710c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
711d49c4288SYinghai Lu
712d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7136fc108a0SJan Beulich	def_bool y
714d949f36fSLinus Torvalds	# MCE code calls memory_failure():
715d949f36fSLinus Torvalds	depends on X86_MCE
716d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
717d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
718d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
719d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
720d949f36fSLinus Torvalds
72183125a3aSAlessandro Rubiniconfig STA2X11
72283125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72383125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72483125a3aSAlessandro Rubini	select SWIOTLB
72583125a3aSAlessandro Rubini	select MFD_STA2X11
7260145071bSLinus Walleij	select GPIOLIB
727a7f7f624SMasahiro Yamada	help
72883125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
72983125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73083125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73183125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73283125a3aSAlessandro Rubini	  standard PC machines.
73383125a3aSAlessandro Rubini
73482148d1dSShérabconfig X86_32_IRIS
73582148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73682148d1dSShérab	depends on X86_32
737a7f7f624SMasahiro Yamada	help
73882148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
73982148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74082148d1dSShérab	  needed to do so, which is what this module does at
74182148d1dSShérab	  kernel shutdown.
74282148d1dSShérab
74382148d1dSShérab	  This is only for Iris machines from EuroBraille.
74482148d1dSShérab
74582148d1dSShérab	  If unused, say N.
74682148d1dSShérab
747ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7483c2362e6SHarvey Harrison	def_bool y
7493c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
750a87d0914SKen Chen	depends on X86
751a7f7f624SMasahiro Yamada	help
752506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
753506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
754506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
755506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
756506f1d07SSam Ravnborg
757506f1d07SSam Ravnborg	  If in doubt, say "Y".
758506f1d07SSam Ravnborg
7596276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7606276a074SBorislav Petkov	bool "Linux guest support"
761a7f7f624SMasahiro Yamada	help
7626276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7636276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7646276a074SBorislav Petkov	  setup.
765506f1d07SSam Ravnborg
7666276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7676276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
768506f1d07SSam Ravnborg
7696276a074SBorislav Petkovif HYPERVISOR_GUEST
770506f1d07SSam Ravnborg
771e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
772e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
773a7f7f624SMasahiro Yamada	help
774e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
775e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
776e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
777e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
778e61bd94aSEduardo Pereira Habkost
779c00a280aSJuergen Grossconfig PARAVIRT_XXL
780c00a280aSJuergen Gross	bool
781c00a280aSJuergen Gross
7826276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7836276a074SBorislav Petkov	bool "paravirt-ops debugging"
7846276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
785a7f7f624SMasahiro Yamada	help
7866276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7876276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7886276a074SBorislav Petkov
789b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
790b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7916ea30386SKees Cook	depends on PARAVIRT && SMP
792a7f7f624SMasahiro Yamada	help
793b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
794b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
795b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
796b4ecc126SJeremy Fitzhardinge
7974c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7984c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
799b4ecc126SJeremy Fitzhardinge
8004c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
801b4ecc126SJeremy Fitzhardinge
802ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
803ecca2502SZhao Yakui	def_bool n
804ecca2502SZhao Yakui
8056276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8066276a074SBorislav Petkov
8076276a074SBorislav Petkovconfig KVM_GUEST
8086276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8096276a074SBorislav Petkov	depends on PARAVIRT
8106276a074SBorislav Petkov	select PARAVIRT_CLOCK
811a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
812b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8136276a074SBorislav Petkov	default y
814a7f7f624SMasahiro Yamada	help
8156276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8166276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8176276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8186276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8196276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8206276a074SBorislav Petkov
821a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
822a1c4423bSMarcelo Tosatti	def_bool n
823a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
824a1c4423bSMarcelo Tosatti	help
825a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
826a1c4423bSMarcelo Tosatti
8277733607fSMaran Wilsonconfig PVH
8287733607fSMaran Wilson	bool "Support for running PVH guests"
829a7f7f624SMasahiro Yamada	help
8307733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8317733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8327733607fSMaran Wilson
8336276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8346276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8356276a074SBorislav Petkov	depends on PARAVIRT
836a7f7f624SMasahiro Yamada	help
8376276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8386276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8396276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8406276a074SBorislav Petkov	  that, there can be a small performance impact.
8416276a074SBorislav Petkov
8426276a074SBorislav Petkov	  If in doubt, say N here.
8436276a074SBorislav Petkov
8447af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8457af192c9SGerd Hoffmann	bool
8467af192c9SGerd Hoffmann
8474a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8484a362601SJan Kiszka	bool "Jailhouse non-root cell support"
849abde587bSArnd Bergmann	depends on X86_64 && PCI
85087e65d05SJan Kiszka	select X86_PM_TIMER
851a7f7f624SMasahiro Yamada	help
8524a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8534a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8544a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8554a362601SJan Kiszka
856ec7972c9SZhao Yakuiconfig ACRN_GUEST
857ec7972c9SZhao Yakui	bool "ACRN Guest support"
858ec7972c9SZhao Yakui	depends on X86_64
859498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
860ec7972c9SZhao Yakui	help
861ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
862ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
863ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
864ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
865ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
866ec7972c9SZhao Yakui
8676276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86897349135SJeremy Fitzhardinge
869506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
870506f1d07SSam Ravnborg
871506f1d07SSam Ravnborgconfig HPET_TIMER
8723c2362e6SHarvey Harrison	def_bool X86_64
873506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
874a7f7f624SMasahiro Yamada	help
875506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
876506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
877506f1d07SSam Ravnborg	  present.
878506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
879506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
880506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8814e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8824e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
883506f1d07SSam Ravnborg
884506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
885506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
886506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
887506f1d07SSam Ravnborg
888506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
889506f1d07SSam Ravnborg
890506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8913c2362e6SHarvey Harrison	def_bool y
8929d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
893506f1d07SSam Ravnborg
8946a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
895506f1d07SSam Ravnborg# The code disables itself when not needed.
8967ae9392cSThomas Petazzoniconfig DMI
8977ae9392cSThomas Petazzoni	default y
898cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8996a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
900a7f7f624SMasahiro Yamada	help
9017ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9027ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9037ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9047ae9392cSThomas Petazzoni	  BIOS code.
9057ae9392cSThomas Petazzoni
906506f1d07SSam Ravnborgconfig GART_IOMMU
90738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9082f9237d4SChristoph Hellwig	select DMA_OPS
909a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
910506f1d07SSam Ravnborg	select SWIOTLB
91123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
912a7f7f624SMasahiro Yamada	help
913ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
914ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
915ced3c42cSIngo Molnar
916ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
917ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
918ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
919ced3c42cSIngo Molnar
920ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
921ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
924ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
925ced3c42cSIngo Molnar	  32-bit limited device.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  If unsure, say Y.
928506f1d07SSam Ravnborg
9291184dc2fSMike Travisconfig MAXSMP
930ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9316ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93236f5101aSMike Travis	select CPUMASK_OFFSTACK
933a7f7f624SMasahiro Yamada	help
934ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9351184dc2fSMike Travis	  If unsure, say N.
936506f1d07SSam Ravnborg
937aec6487eSIngo Molnar#
938aec6487eSIngo Molnar# The maximum number of CPUs supported:
939aec6487eSIngo Molnar#
940aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
941aec6487eSIngo Molnar# and which can be configured interactively in the
942aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
943aec6487eSIngo Molnar#
944aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
945aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
948aec6487eSIngo Molnar#   interactive configuration. )
949aec6487eSIngo Molnar#
950a0d0bb4dSRandy Dunlap
951aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
952a0d0bb4dSRandy Dunlap	int
953aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
954a0d0bb4dSRandy Dunlap	default    1 if !SMP
955a0d0bb4dSRandy Dunlap	default    2
956a0d0bb4dSRandy Dunlap
957aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
958a0d0bb4dSRandy Dunlap	int
959a0d0bb4dSRandy Dunlap	depends on X86_32
960aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
961aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
962a0d0bb4dSRandy Dunlap	default    1 if !SMP
963a0d0bb4dSRandy Dunlap
964aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
965a0d0bb4dSRandy Dunlap	int
966a0d0bb4dSRandy Dunlap	depends on X86_64
9671edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9681edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970aec6487eSIngo Molnar
971aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
972aec6487eSIngo Molnar	int
973aec6487eSIngo Molnar	depends on X86_32
974aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
975aec6487eSIngo Molnar	default    8 if  SMP
976aec6487eSIngo Molnar	default    1 if !SMP
977aec6487eSIngo Molnar
978aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
979aec6487eSIngo Molnar	int
980aec6487eSIngo Molnar	depends on X86_64
981a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
982a0d0bb4dSRandy Dunlap	default   64 if  SMP
983aec6487eSIngo Molnar	default    1 if !SMP
984a0d0bb4dSRandy Dunlap
985506f1d07SSam Ravnborgconfig NR_CPUS
98636f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
987aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
988aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
989a7f7f624SMasahiro Yamada	help
990506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
991bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
992cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
993506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
994506f1d07SSam Ravnborg
995aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
996aec6487eSIngo Molnar	  to the kernel image.
997506f1d07SSam Ravnborg
998506f1d07SSam Ravnborgconfig SCHED_SMT
999dbe73364SThomas Gleixner	def_bool y if SMP
1000506f1d07SSam Ravnborg
1001506f1d07SSam Ravnborgconfig SCHED_MC
10023c2362e6SHarvey Harrison	def_bool y
10033c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1004c8e56d20SBorislav Petkov	depends on SMP
1005a7f7f624SMasahiro Yamada	help
1006506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1007506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1008506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1009506f1d07SSam Ravnborg
1010de966cf4STim Chenconfig SCHED_MC_PRIO
1011de966cf4STim Chen	bool "CPU core priorities scheduler support"
10120a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10130a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10140a21fc12SIngo Molnar	select CPU_FREQ
1015de966cf4STim Chen	default y
1016a7f7f624SMasahiro Yamada	help
1017de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1018de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1019de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1020de966cf4STim Chen	  single threaded workloads) than others.
1021de966cf4STim Chen
1022de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1023de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1024de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1025de966cf4STim Chen	  overall system performance can be achieved.
1026de966cf4STim Chen
1027de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1028de966cf4STim Chen
1029de966cf4STim Chen	  If unsure say Y here.
10305e76b2abSTim Chen
103130b8b006SThomas Gleixnerconfig UP_LATE_INIT
103230b8b006SThomas Gleixner	def_bool y
1033ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
103430b8b006SThomas Gleixner
1035506f1d07SSam Ravnborgconfig X86_UP_APIC
103650849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
103750849eefSJan Beulich	default PCI_MSI
103838a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1039a7f7f624SMasahiro Yamada	help
1040506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1041506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1042506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1043506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1044506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1045506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1046506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1047506f1d07SSam Ravnborg	  lockups.
1048506f1d07SSam Ravnborg
1049506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1050506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1051506f1d07SSam Ravnborg	depends on X86_UP_APIC
1052a7f7f624SMasahiro Yamada	help
1053506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1054506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1055506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1056506f1d07SSam Ravnborg
1057506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1058506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1059506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1060506f1d07SSam Ravnborg
1061506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10623c2362e6SHarvey Harrison	def_bool y
10630dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1064b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
106552f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1066506f1d07SSam Ravnborg
1067506f1d07SSam Ravnborgconfig X86_IO_APIC
1068b1da1e71SJan Beulich	def_bool y
1069b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1070506f1d07SSam Ravnborg
107141b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107241b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
107341b9eb26SStefan Assmann	depends on X86_IO_APIC
1074a7f7f624SMasahiro Yamada	help
107541b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
107641b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
107741b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
107841b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
107941b9eb26SStefan Assmann
108041b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108141b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108241b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
108341b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
108441b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
108541b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
108641b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
108741b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
108841b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
108941b9eb26SStefan Assmann	  down (vital) interrupt lines.
109041b9eb26SStefan Assmann
109141b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109241b9eb26SStefan Assmann	  increased on these systems.
109341b9eb26SStefan Assmann
1094506f1d07SSam Ravnborgconfig X86_MCE
1095bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1096648ed940SChen, Gong	select GENERIC_ALLOCATOR
1097e57dbaf7SBorislav Petkov	default y
1098a7f7f624SMasahiro Yamada	help
1099bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1100bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1101506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1102bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11034efc0670SAndi Kleen
11045de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11055de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11065de97c9fSTony Luck	depends on X86_MCE
1107a7f7f624SMasahiro Yamada	help
11085de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11095de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11105de97c9fSTony Luck	  rasdaemon solution.
11115de97c9fSTony Luck
1112506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11133c2362e6SHarvey Harrison	def_bool y
11143c2362e6SHarvey Harrison	prompt "Intel MCE features"
1115c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1116a7f7f624SMasahiro Yamada	help
1117506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1118506f1d07SSam Ravnborg	   the thermal monitor.
1119506f1d07SSam Ravnborg
1120506f1d07SSam Ravnborgconfig X86_MCE_AMD
11213c2362e6SHarvey Harrison	def_bool y
11223c2362e6SHarvey Harrison	prompt "AMD MCE features"
1123f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1124a7f7f624SMasahiro Yamada	help
1125506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1126506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1127506f1d07SSam Ravnborg
11284efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11296fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1130c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1131a7f7f624SMasahiro Yamada	help
11324efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11335065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11344efc0670SAndi Kleen	  line.
11354efc0670SAndi Kleen
1136b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1137b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11386fc108a0SJan Beulich	def_bool y
1139b2762686SAndi Kleen
1140ea149b36SAndi Kleenconfig X86_MCE_INJECT
1141bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1142ea149b36SAndi Kleen	tristate "Machine check injector support"
1143a7f7f624SMasahiro Yamada	help
1144ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1145ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1146ea149b36SAndi Kleen	  QA it is safe to say n.
1147ea149b36SAndi Kleen
11484efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11494efc0670SAndi Kleen	def_bool y
11505bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11514efc0670SAndi Kleen
115207dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1153e633c65aSKan Liang
11545aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11551e642812SIngo Molnar	bool "Legacy VM86 support"
1156506f1d07SSam Ravnborg	depends on X86_32
1157a7f7f624SMasahiro Yamada	help
11585aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11595aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11605aef51c3SAndy Lutomirski
11615aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11625aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11635aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11645aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11655aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11661e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11671e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11681e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11691e642812SIngo Molnar	  enable this option.
11705aef51c3SAndy Lutomirski
11711e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11721e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11731e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11741e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11755aef51c3SAndy Lutomirski
11761e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11771e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11785aef51c3SAndy Lutomirski
11791e642812SIngo Molnar	  If unsure, say N here.
11805aef51c3SAndy Lutomirski
11815aef51c3SAndy Lutomirskiconfig VM86
11825aef51c3SAndy Lutomirski	bool
11835aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
118434273f41SH. Peter Anvin
118534273f41SH. Peter Anvinconfig X86_16BIT
118634273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
118734273f41SH. Peter Anvin	default y
1188a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1189a7f7f624SMasahiro Yamada	help
119034273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119134273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119234273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
119334273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
119434273f41SH. Peter Anvin
119534273f41SH. Peter Anvinconfig X86_ESPFIX32
119634273f41SH. Peter Anvin	def_bool y
119734273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1198506f1d07SSam Ravnborg
1199197725deSH. Peter Anvinconfig X86_ESPFIX64
1200197725deSH. Peter Anvin	def_bool y
120134273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1202506f1d07SSam Ravnborg
12031ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12041ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12051ad83c85SAndy Lutomirski	default y
12061ad83c85SAndy Lutomirski	depends on X86_64
1207a7f7f624SMasahiro Yamada	help
12081ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12091ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12101ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12111ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12121ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12131ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12141ad83c85SAndy Lutomirski
12151ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12161ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12171ad83c85SAndy Lutomirski
12181ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12191ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12201ad83c85SAndy Lutomirski
1221111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1222111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1223a24ca997SThomas Gleixner	default y
1224a7f7f624SMasahiro Yamada	help
1225111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1226111e7b15SThomas Gleixner	  for legacy applications.
1227111e7b15SThomas Gleixner
1228c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1229c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1230c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1231c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1232c8137aceSThomas Gleixner	  modules.
1233c8137aceSThomas Gleixner
1234c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1235c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1236a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1237a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1238c8137aceSThomas Gleixner
1239506f1d07SSam Ravnborgconfig TOSHIBA
1240506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1241506f1d07SSam Ravnborg	depends on X86_32
1242a7f7f624SMasahiro Yamada	help
1243506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1244506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1245506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1246506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1247506f1d07SSam Ravnborg
1248506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1249506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1250506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1251506f1d07SSam Ravnborg
1252506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1253506f1d07SSam Ravnborg	  Say N otherwise.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborgconfig I8K
1256039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1257949a9d70SJean Delvare	select HWMON
1258039ae585SPali Rohár	select SENSORS_DELL_SMM
1259a7f7f624SMasahiro Yamada	help
1260039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1261039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1262039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1263039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1264039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1265039ae585SPali Rohár	  needed userspace package i8kutils.
1266506f1d07SSam Ravnborg
1267039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1268039ae585SPali Rohár	  use userspace package i8kutils.
1269506f1d07SSam Ravnborg	  Say N otherwise.
1270506f1d07SSam Ravnborg
1271506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12729ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12739ba16087SJan Beulich	depends on X86_32
1274a7f7f624SMasahiro Yamada	help
1275506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1276506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1277506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1278506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1279506f1d07SSam Ravnborg	  system.
1280506f1d07SSam Ravnborg
1281506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12825e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1283506f1d07SSam Ravnborg
1284506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1285506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1286506f1d07SSam Ravnborg	  Say N otherwise.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborgconfig MICROCODE
12899a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12909a2bc335SBorislav Petkov	default y
129180030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1292a7f7f624SMasahiro Yamada	help
1293506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12945f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12955f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12965f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12975f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12985f9c01aaSBorislav Petkov	  the Linux kernel.
1299506f1d07SSam Ravnborg
13005f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1301cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13025f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13035f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1304506f1d07SSam Ravnborg
1305c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1306c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1307c508c46eSBenjamin Gilbert	  config option.
1308506f1d07SSam Ravnborg
13098d86f390SPeter Orubaconfig MICROCODE_INTEL
1310e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13118d86f390SPeter Oruba	depends on MICROCODE
13128d86f390SPeter Oruba	default MICROCODE
1313a7f7f624SMasahiro Yamada	help
13148d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13158d86f390SPeter Oruba	  processors.
13168d86f390SPeter Oruba
1317b8989db9SAlan	  For the current Intel microcode data package go to
1318b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1319b8989db9SAlan	  'Linux Processor Microcode Data File'.
13208d86f390SPeter Oruba
132180cc9f10SPeter Orubaconfig MICROCODE_AMD
1322e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132380cc9f10SPeter Oruba	depends on MICROCODE
1324a7f7f624SMasahiro Yamada	help
132580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
132680cc9f10SPeter Oruba	  processors will be enabled.
132780cc9f10SPeter Oruba
1328506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1329c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1330c02f48e0SBorislav Petkov	default n
1331506f1d07SSam Ravnborg	depends on MICROCODE
1332a7f7f624SMasahiro Yamada	help
1333c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1334c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1335c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1336c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1337c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1338cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1339506f1d07SSam Ravnborg
1340506f1d07SSam Ravnborgconfig X86_MSR
1341506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1342a7f7f624SMasahiro Yamada	help
1343506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1344506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1345506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1346506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1347506f1d07SSam Ravnborg	  systems.
1348506f1d07SSam Ravnborg
1349506f1d07SSam Ravnborgconfig X86_CPUID
1350506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1351a7f7f624SMasahiro Yamada	help
1352506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1353506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1354506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1355506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1356506f1d07SSam Ravnborg
1357506f1d07SSam Ravnborgchoice
1358506f1d07SSam Ravnborg	prompt "High Memory Support"
13596fc108a0SJan Beulich	default HIGHMEM4G
1360506f1d07SSam Ravnborg	depends on X86_32
1361506f1d07SSam Ravnborg
1362506f1d07SSam Ravnborgconfig NOHIGHMEM
1363506f1d07SSam Ravnborg	bool "off"
1364a7f7f624SMasahiro Yamada	help
1365506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1366506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1367506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1368506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1369506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1370506f1d07SSam Ravnborg	  "high memory".
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1373506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1374506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1375506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1376506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1377506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1378506f1d07SSam Ravnborg	  possible.
1379506f1d07SSam Ravnborg
1380506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1381506f1d07SSam Ravnborg	  answer "4GB" here.
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1384506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1385506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1386506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1387506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1388506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1391506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1392506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1393506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1394506f1d07SSam Ravnborg	  kernel at boot time.)
1395506f1d07SSam Ravnborg
1396506f1d07SSam Ravnborg	  If unsure, say "off".
1397506f1d07SSam Ravnborg
1398506f1d07SSam Ravnborgconfig HIGHMEM4G
1399506f1d07SSam Ravnborg	bool "4GB"
1400a7f7f624SMasahiro Yamada	help
1401506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1402506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1403506f1d07SSam Ravnborg
1404506f1d07SSam Ravnborgconfig HIGHMEM64G
1405506f1d07SSam Ravnborg	bool "64GB"
140669b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1407506f1d07SSam Ravnborg	select X86_PAE
1408a7f7f624SMasahiro Yamada	help
1409506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1410506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1411506f1d07SSam Ravnborg
1412506f1d07SSam Ravnborgendchoice
1413506f1d07SSam Ravnborg
1414506f1d07SSam Ravnborgchoice
14156a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1416506f1d07SSam Ravnborg	default VMSPLIT_3G
1417506f1d07SSam Ravnborg	depends on X86_32
1418a7f7f624SMasahiro Yamada	help
1419506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1422506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1423506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1424506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1425506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1426506f1d07SSam Ravnborg	  available to user programs, making the address space there
1427506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1428506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1429506f1d07SSam Ravnborg	  kernel modules.
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1432506f1d07SSam Ravnborg	  option alone!
1433506f1d07SSam Ravnborg
1434506f1d07SSam Ravnborg	config VMSPLIT_3G
1435506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1436506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1437506f1d07SSam Ravnborg		depends on !X86_PAE
1438506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1439506f1d07SSam Ravnborg	config VMSPLIT_2G
1440506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1441506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1442506f1d07SSam Ravnborg		depends on !X86_PAE
1443506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1444506f1d07SSam Ravnborg	config VMSPLIT_1G
1445506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1446506f1d07SSam Ravnborgendchoice
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborgconfig PAGE_OFFSET
1449506f1d07SSam Ravnborg	hex
1450506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1451506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1452506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1453506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1454506f1d07SSam Ravnborg	default 0xC0000000
1455506f1d07SSam Ravnborg	depends on X86_32
1456506f1d07SSam Ravnborg
1457506f1d07SSam Ravnborgconfig HIGHMEM
14583c2362e6SHarvey Harrison	def_bool y
1459506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1460506f1d07SSam Ravnborg
1461506f1d07SSam Ravnborgconfig X86_PAE
14629ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1463506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1464d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14659d99c712SChristian Melki	select SWIOTLB
1466a7f7f624SMasahiro Yamada	help
1467506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1468506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1469506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1470506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1471506f1d07SSam Ravnborg
147277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
147418ec1eafSKirill A. Shutemov	default y
1475eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1476162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147777ef56e4SKirill A. Shutemov	depends on X86_64
1478a7f7f624SMasahiro Yamada	help
147977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
148077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148177ef56e4SKirill A. Shutemov	  physical address space.
148277ef56e4SKirill A. Shutemov
148377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
148477ef56e4SKirill A. Shutemov
14856657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14866657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148777ef56e4SKirill A. Shutemov
1488cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
148977ef56e4SKirill A. Shutemov	  information.
149077ef56e4SKirill A. Shutemov
149177ef56e4SKirill A. Shutemov	  Say N if unsure.
149277ef56e4SKirill A. Shutemov
149310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1494e5008abeSLuis R. Rodriguez	def_bool y
14952e1da13fSVlastimil Babka	depends on X86_64
1496a7f7f624SMasahiro Yamada	help
149710971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149810971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149910971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
150010971ab2SIngo Molnar	  that we have them enabled.
15019e899816SNick Piggin
15025c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15035c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15045c280cf6SThomas Gleixner	depends on DEBUG_FS
1505a7f7f624SMasahiro Yamada	help
1506b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1507a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15085c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15095c280cf6SThomas Gleixner
15107744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15117744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15127744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
151382fef0adSDavid Rientjes	select DMA_COHERENT_POOL
151494d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1515ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15169087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1517597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1518a7f7f624SMasahiro Yamada	help
15197744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15207744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15217744ccdbSTom Lendacky	  Encryption (SME).
15227744ccdbSTom Lendacky
15237744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15247744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15257744ccdbSTom Lendacky	default y
15267744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1527a7f7f624SMasahiro Yamada	help
15287744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15297744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15307744ccdbSTom Lendacky
15317744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15327744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15337744ccdbSTom Lendacky
15347744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15357744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15367744ccdbSTom Lendacky
1537506f1d07SSam Ravnborg# Common NUMA Features
1538506f1d07SSam Ravnborgconfig NUMA
1539e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1540506f1d07SSam Ravnborg	depends on SMP
1541b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1542b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1543a7f7f624SMasahiro Yamada	help
1544e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1545fd51b2d7SKOSAKI Motohiro
1546506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1547506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1548506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1549506f1d07SSam Ravnborg
1550c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1551fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1552fd51b2d7SKOSAKI Motohiro
1553b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15547cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1555fd51b2d7SKOSAKI Motohiro
1556fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1557506f1d07SSam Ravnborg
1558eec1d4faSHans Rosenfeldconfig AMD_NUMA
15593c2362e6SHarvey Harrison	def_bool y
15603c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15615da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1562a7f7f624SMasahiro Yamada	help
1563eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1564eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1565eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1566eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1567eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1568506f1d07SSam Ravnborg
1569506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15703c2362e6SHarvey Harrison	def_bool y
15713c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1572506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1573506f1d07SSam Ravnborg	select ACPI_NUMA
1574a7f7f624SMasahiro Yamada	help
1575506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1576506f1d07SSam Ravnborg
1577506f1d07SSam Ravnborgconfig NUMA_EMU
1578506f1d07SSam Ravnborg	bool "NUMA emulation"
15791b7e03efSTejun Heo	depends on NUMA
1580a7f7f624SMasahiro Yamada	help
1581506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1582506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1583506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1584506f1d07SSam Ravnborg
1585506f1d07SSam Ravnborgconfig NODES_SHIFT
1586d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158751591e31SDavid Rientjes	range 1 10
158851591e31SDavid Rientjes	default "10" if MAXSMP
1589506f1d07SSam Ravnborg	default "6" if X86_64
1590506f1d07SSam Ravnborg	default "3"
1591506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
1592a7f7f624SMasahiro Yamada	help
15931184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1594692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1595506f1d07SSam Ravnborg
1596506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1597506f1d07SSam Ravnborg	def_bool y
15983b16651fSTejun Heo	depends on X86_32 && !NUMA
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1601506f1d07SSam Ravnborg	def_bool y
16026ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1603506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1604506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1605506f1d07SSam Ravnborg
16063b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16076ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16083b16651fSTejun Heo
1609506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1610506f1d07SSam Ravnborg	def_bool y
1611b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1614a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16153120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1616a0842b70SToshi Kani	help
1617a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1618cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1619a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1620506f1d07SSam Ravnborg
16213b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16223b16651fSTejun Heo	def_bool y
16233b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16243b16651fSTejun Heo
1625a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1626a29815a3SAvi Kivity	hex
1627a29815a3SAvi Kivity	default 0 if X86_32
1628a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1629a29815a3SAvi Kivity
16307a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16317a67832cSDan Williams	bool
16327a67832cSDan Williams
1633ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16347a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16359f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16369f53f9faSDan Williams	depends on BLK_DEV
16377a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16387b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16399f53f9faSDan Williams	select LIBNVDIMM
1640ec776ef6SChristoph Hellwig	help
1641ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1642ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1643ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1644ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1645ec776ef6SChristoph Hellwig
1646ec776ef6SChristoph Hellwig	  Say Y if unsure.
1647ec776ef6SChristoph Hellwig
1648506f1d07SSam Ravnborgconfig HIGHPTE
1649506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16506fc108a0SJan Beulich	depends on HIGHMEM
1651a7f7f624SMasahiro Yamada	help
1652506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1653506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1654506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1655506f1d07SSam Ravnborg	  entries in high memory.
1656506f1d07SSam Ravnborg
16579f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16589f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1659a7f7f624SMasahiro Yamada	help
16609f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16619f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16629f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16639f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16649f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16659f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16669f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16678c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16689f077871SJeremy Fitzhardinge
16699f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16709f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16719f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16729f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16739f077871SJeremy Fitzhardinge
16749f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16759f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16769f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16779f077871SJeremy Fitzhardinge	  memory.
16789f077871SJeremy Fitzhardinge
1679c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1680c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1681c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1682c885df50SJeremy Fitzhardinge	default y
1683a7f7f624SMasahiro Yamada	help
1684c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1685c885df50SJeremy Fitzhardinge	  on or off.
1686c885df50SJeremy Fitzhardinge
16879ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1688d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1689d0cd7425SH. Peter Anvin	default 64
1690d0cd7425SH. Peter Anvin	range 4 640
1691a7f7f624SMasahiro Yamada	help
1692d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1693fc381519SIngo Molnar
1694d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1695d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1696fc381519SIngo Molnar
1697d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1698d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1699d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1700d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1701fc381519SIngo Molnar
1702d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1703d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1704d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1705d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1706d0cd7425SH. Peter Anvin	  entire low memory range.
1707d0cd7425SH. Peter Anvin
1708d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1709d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1710d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1711d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1712d0cd7425SH. Peter Anvin	  typical corruption patterns.
1713d0cd7425SH. Peter Anvin
1714d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1715fc381519SIngo Molnar
1716506f1d07SSam Ravnborgconfig MATH_EMULATION
1717506f1d07SSam Ravnborg	bool
1718a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
171987d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1720a7f7f624SMasahiro Yamada	help
1721506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1722506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1723506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1724506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1725506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1726506f1d07SSam Ravnborg	  coprocessor or this emulation.
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1729506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1730506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1731506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1732506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1733506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1734506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1735506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1738506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1741506f1d07SSam Ravnborg	  kernel, it won't hurt.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborgconfig MTRR
17446fc108a0SJan Beulich	def_bool y
17456a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1746a7f7f624SMasahiro Yamada	help
1747506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1748506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1749506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1750506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1751506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1752506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1753506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1754506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1755506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1756506f1d07SSam Ravnborg
1757506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1758506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1759506f1d07SSam Ravnborg	  as well:
1760506f1d07SSam Ravnborg
1761506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1762506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1763506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1764506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1765506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1766506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1767506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1768506f1d07SSam Ravnborg
1769506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1770506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1771506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1772506f1d07SSam Ravnborg
1773506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1774506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1775506f1d07SSam Ravnborg
1776cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1777506f1d07SSam Ravnborg
177895ffa243SYinghai Luconfig MTRR_SANITIZER
17792ffb3501SYinghai Lu	def_bool y
178095ffa243SYinghai Lu	prompt "MTRR cleanup support"
178195ffa243SYinghai Lu	depends on MTRR
1782a7f7f624SMasahiro Yamada	help
1783aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1784aba3728cSThomas Gleixner	  add writeback entries.
178595ffa243SYinghai Lu
1786aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1787692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1788aba3728cSThomas Gleixner	  mtrr_chunk_size.
178995ffa243SYinghai Lu
17902ffb3501SYinghai Lu	  If unsure, say Y.
179195ffa243SYinghai Lu
179295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1793f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1794f5098d62SYinghai Lu	range 0 1
1795f5098d62SYinghai Lu	default "0"
179695ffa243SYinghai Lu	depends on MTRR_SANITIZER
1797a7f7f624SMasahiro Yamada	help
1798f5098d62SYinghai Lu	  Enable mtrr cleanup default value
179995ffa243SYinghai Lu
180012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180112031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180212031a62SYinghai Lu	range 0 7
180312031a62SYinghai Lu	default "1"
180412031a62SYinghai Lu	depends on MTRR_SANITIZER
1805a7f7f624SMasahiro Yamada	help
180612031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1807aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180812031a62SYinghai Lu
18092e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18106fc108a0SJan Beulich	def_bool y
18116a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18122a8a2719SIngo Molnar	depends on MTRR
1813a7f7f624SMasahiro Yamada	help
18142e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1815042b78e4SVenki Pallipadi
18162e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18172e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18182e5d9c85Svenkatesh.pallipadi@intel.com
18192e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1820042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18212e5d9c85Svenkatesh.pallipadi@intel.com
18222e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18232e5d9c85Svenkatesh.pallipadi@intel.com
182446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
182546cf98cdSVenkatesh Pallipadi	def_bool y
182646cf98cdSVenkatesh Pallipadi	depends on X86_PAT
182746cf98cdSVenkatesh Pallipadi
1828628c6246SH. Peter Anvinconfig ARCH_RANDOM
1829628c6246SH. Peter Anvin	def_bool y
1830628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1831a7f7f624SMasahiro Yamada	help
1832628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1833628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1834628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1835628c6246SH. Peter Anvin	  secure hardware random number generator.
1836628c6246SH. Peter Anvin
183751ae4a2dSH. Peter Anvinconfig X86_SMAP
183851ae4a2dSH. Peter Anvin	def_bool y
183951ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1840a7f7f624SMasahiro Yamada	help
184151ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
184251ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
184351ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
184451ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
184551ae4a2dSH. Peter Anvin
184651ae4a2dSH. Peter Anvin	  If unsure, say Y.
184751ae4a2dSH. Peter Anvin
1848b971880fSBabu Mogerconfig X86_UMIP
1849796ebc81SRicardo Neri	def_bool y
1850b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1851a7f7f624SMasahiro Yamada	help
1852b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1853b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1854b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1855b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1856b971880fSBabu Moger	  information about the hardware state.
1857796ebc81SRicardo Neri
1858796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1859796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1860796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1861796ebc81SRicardo Neri	  results are dummy.
1862aa35f896SRicardo Neri
186335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
186438f3e775SBabu Moger	prompt "Memory Protection Keys"
186535e97790SDave Hansen	def_bool y
1866284244a9SDave Hansen	# Note: only available in 64-bit mode
186738f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
186852c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
186952c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1870a7f7f624SMasahiro Yamada	help
1871284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1872284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1873284244a9SDave Hansen	  page tables when an application changes protection domains.
1874284244a9SDave Hansen
18751eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1876284244a9SDave Hansen
1877284244a9SDave Hansen	  If unsure, say y.
187835e97790SDave Hansen
1879db616173SMichal Hockochoice
1880db616173SMichal Hocko	prompt "TSX enable mode"
1881db616173SMichal Hocko	depends on CPU_SUP_INTEL
1882db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1883db616173SMichal Hocko	help
1884db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1885db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1886db616173SMichal Hocko	  can lead to a noticeable performance boost.
1887db616173SMichal Hocko
1888db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1889db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1890db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1891db616173SMichal Hocko
1892db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1893db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1894db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1895db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1896db616173SMichal Hocko	  for the particular machine.
1897db616173SMichal Hocko
1898db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1899db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1900db616173SMichal Hocko	  details.
1901db616173SMichal Hocko
1902db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1903db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1904db616173SMichal Hocko	  relevant.
1905db616173SMichal Hocko
1906db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1907db616173SMichal Hocko	bool "off"
1908db616173SMichal Hocko	help
1909db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1910db616173SMichal Hocko
1911db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1912db616173SMichal Hocko	bool "on"
1913db616173SMichal Hocko	help
1914db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1915db616173SMichal Hocko	  line parameter.
1916db616173SMichal Hocko
1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1918db616173SMichal Hocko	bool "auto"
1919db616173SMichal Hocko	help
1920db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1921db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1922db616173SMichal Hockoendchoice
1923db616173SMichal Hocko
1924e7e05452SSean Christophersonconfig X86_SGX
1925e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1926e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1927e7e05452SSean Christopherson	depends on CRYPTO=y
1928e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1929e7e05452SSean Christopherson	select SRCU
1930e7e05452SSean Christopherson	select MMU_NOTIFIER
1931e7e05452SSean Christopherson	help
1932e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1933e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1934e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1935e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1936e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1937e7e05452SSean Christopherson	  hardware.
1938e7e05452SSean Christopherson
1939e7e05452SSean Christopherson	  If unsure, say N.
1940e7e05452SSean Christopherson
1941506f1d07SSam Ravnborgconfig EFI
19429ba16087SJan Beulich	bool "EFI runtime service support"
19435b83683fSHuang, Ying	depends on ACPI
1944f6ce5002SSergey Vlasov	select UCS2_STRING
1945022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1946a7f7f624SMasahiro Yamada	help
19478b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1948506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1949506f1d07SSam Ravnborg
19508b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19518b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19528b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19538b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19548b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19558b2cb7a8SHuang, Ying	  platforms.
1956506f1d07SSam Ravnborg
1957291f3632SMatt Flemingconfig EFI_STUB
1958291f3632SMatt Fleming	bool "EFI stub support"
1959b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19608f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19617b2a583aSMatt Fleming	select RELOCATABLE
1962a7f7f624SMasahiro Yamada	help
1963291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1964291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1965291f3632SMatt Fleming
19664f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19670c759662SMatt Fleming
19687d453eeeSMatt Flemingconfig EFI_MIXED
19697d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19707d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1971a7f7f624SMasahiro Yamada	help
19727d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19737d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19747d453eeeSMatt Fleming	   mode.
19757d453eeeSMatt Fleming
19767d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19777d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19787d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19797d453eeeSMatt Fleming
19807d453eeeSMatt Fleming	   If unsure, say N.
19817d453eeeSMatt Fleming
19828636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1983506f1d07SSam Ravnborg
1984506f1d07SSam Ravnborgconfig KEXEC
1985506f1d07SSam Ravnborg	bool "kexec system call"
19862965faa5SDave Young	select KEXEC_CORE
1987a7f7f624SMasahiro Yamada	help
1988506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1989506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1990506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1991506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1992506f1d07SSam Ravnborg
1993506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1994506f1d07SSam Ravnborg
1995506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1996506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1997bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1998bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1999bf220695SGeert Uytterhoeven	  made.
2000506f1d07SSam Ravnborg
200174ca317cSVivek Goyalconfig KEXEC_FILE
200274ca317cSVivek Goyal	bool "kexec file based system call"
20032965faa5SDave Young	select KEXEC_CORE
200474ca317cSVivek Goyal	select BUILD_BIN2C
200574ca317cSVivek Goyal	depends on X86_64
200674ca317cSVivek Goyal	depends on CRYPTO=y
200774ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2008a7f7f624SMasahiro Yamada	help
200974ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
201074ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
201174ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
201274ca317cSVivek Goyal	  accepted by previous system call.
201374ca317cSVivek Goyal
2014b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2015b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2016b799a09fSAKASHI Takahiro
201799d5cadfSJiri Bohacconfig KEXEC_SIG
20188e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201974ca317cSVivek Goyal	depends on KEXEC_FILE
2020a7f7f624SMasahiro Yamada	help
202199d5cadfSJiri Bohac
202299d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
202399d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
202499d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
202599d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
202699d5cadfSJiri Bohac
202799d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
202899d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
202999d5cadfSJiri Bohac	  loaded in order for this to work.
203099d5cadfSJiri Bohac
203199d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
203299d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
203399d5cadfSJiri Bohac	depends on KEXEC_SIG
2034a7f7f624SMasahiro Yamada	help
20358e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2036d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20378e7d8381SVivek Goyal
20388e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20398e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
204099d5cadfSJiri Bohac	depends on KEXEC_SIG
20418e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20428e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2043a7f7f624SMasahiro Yamada	help
20448e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20458e7d8381SVivek Goyal
2046506f1d07SSam Ravnborgconfig CRASH_DUMP
204704b69447SPavel Machek	bool "kernel crash dumps"
2048506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2049a7f7f624SMasahiro Yamada	help
2050506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2051506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2052506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2053506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2054506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2055506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2056506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2057506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2058330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2059506f1d07SSam Ravnborg
20603ab83521SHuang Yingconfig KEXEC_JUMP
20616ea30386SKees Cook	bool "kexec jump"
2062fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2063a7f7f624SMasahiro Yamada	help
206489081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
206589081d17SHuang Ying	  code in physical address mode via KEXEC
20663ab83521SHuang Ying
2067506f1d07SSam Ravnborgconfig PHYSICAL_START
20686a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2069ceefccc9SH. Peter Anvin	default "0x1000000"
2070a7f7f624SMasahiro Yamada	help
2071506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2072506f1d07SSam Ravnborg
2073506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2074506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2075506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2076506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2077506f1d07SSam Ravnborg	  address.
2078506f1d07SSam Ravnborg
2079506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2080506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2081506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2082506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2083506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2084506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2085506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2086506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2087506f1d07SSam Ravnborg
2088ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2089ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2090ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2091ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2092ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2093ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2094ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2095330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2096ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2097506f1d07SSam Ravnborg
2098506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2099506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2100506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2101506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2102506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2103506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2104506f1d07SSam Ravnborg	  line.
2105506f1d07SSam Ravnborg
2106506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2107506f1d07SSam Ravnborg
2108506f1d07SSam Ravnborgconfig RELOCATABLE
210926717808SH. Peter Anvin	bool "Build a relocatable kernel"
211026717808SH. Peter Anvin	default y
2111a7f7f624SMasahiro Yamada	help
2112506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2113506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2114506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2115506f1d07SSam Ravnborg	  but are discarded at runtime.
2116506f1d07SSam Ravnborg
2117506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2118506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2119506f1d07SSam Ravnborg	  kernel.
2120506f1d07SSam Ravnborg
2121506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2122506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21238ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2124506f1d07SSam Ravnborg
21258ab3820fSKees Cookconfig RANDOMIZE_BASE
2126e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21278ab3820fSKees Cook	depends on RELOCATABLE
21286807c846SIngo Molnar	default y
2129a7f7f624SMasahiro Yamada	help
2130e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2131e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2132e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2133e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2134e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2135e8581e3dSBaoquan He	  code internals.
2136e8581e3dSBaoquan He
2137ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2138ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2139ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2140ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2141ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2142ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2143ed9f007eSKees Cook
2144ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2145ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2146ed9f007eSKees Cook	  512MB (8 bits of entropy).
21478ab3820fSKees Cook
2148a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2149e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2150e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2151ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2152ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2153ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2154ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2155ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2156ed9f007eSKees Cook	  limited due to memory layouts.
2157e8581e3dSBaoquan He
21586807c846SIngo Molnar	  If unsure, say Y.
2159da2b6fb9SKees Cook
21608ab3820fSKees Cook# Relocation on x86 needs some additional build support
2161845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2162845adf72SH. Peter Anvin	def_bool y
21638ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2164845adf72SH. Peter Anvin
2165506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2166a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21678ab3820fSKees Cook	default "0x200000"
2168a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2169a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2170a7f7f624SMasahiro Yamada	help
2171506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2172506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2173506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2174506f1d07SSam Ravnborg
2175506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2176506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2177506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2178506f1d07SSam Ravnborg
2179506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2180506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2181506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2182506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2183506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2184506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2185506f1d07SSam Ravnborg	  above alignment restrictions.
2186506f1d07SSam Ravnborg
2187a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2188a0215061SKees Cook	  this value must be a multiple of 0x200000.
2189a0215061SKees Cook
2190506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2191506f1d07SSam Ravnborg
2192eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2193eedb92abSKirill A. Shutemov	bool
2194a7f7f624SMasahiro Yamada	help
2195eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2196eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2197eedb92abSKirill A. Shutemov
21980483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21990483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22000483e1faSThomas Garnier	depends on X86_64
22010483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2202eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22030483e1faSThomas Garnier	default RANDOMIZE_BASE
2204a7f7f624SMasahiro Yamada	help
22050483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22060483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22070483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22080483e1faSThomas Garnier
22090483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22100483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22110483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22120483e1faSThomas Garnier	   addresses for each memory section.
22130483e1faSThomas Garnier
22146807c846SIngo Molnar	   If unsure, say Y.
22150483e1faSThomas Garnier
221690397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
221790397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
221890397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
221990397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
222090397a41SThomas Garnier	default "0x0"
222190397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222290397a41SThomas Garnier	range 0x0 0x40
2223a7f7f624SMasahiro Yamada	help
222490397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
222590397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
222690397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
222790397a41SThomas Garnier	   address randomization.
222890397a41SThomas Garnier
222990397a41SThomas Garnier	   If unsure, leave at the default value.
223090397a41SThomas Garnier
2231506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2232bebd024eSThomas Gleixner	def_bool y
223340b31360SStephen Rothwell	depends on SMP
2234506f1d07SSam Ravnborg
223580aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
223680aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22372c922cd0SKees Cook	depends on HOTPLUG_CPU
2238a7f7f624SMasahiro Yamada	help
223980aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224080aa1dffSFenghua Yu
224180aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224280aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224380aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
224480aa1dffSFenghua Yu
224580aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224680aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
224780aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224880aa1dffSFenghua Yu
224980aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225080aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225180aa1dffSFenghua Yu
225280aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225380aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
225480aa1dffSFenghua Yu	  be other CPU0 dependencies.
225580aa1dffSFenghua Yu
225680aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
225780aa1dffSFenghua Yu	  you enable this feature.
225880aa1dffSFenghua Yu
225980aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226080aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226180aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226280aa1dffSFenghua Yu
2263a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2264a71c8bc5SFenghua Yu	def_bool n
2265a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22662c922cd0SKees Cook	depends on HOTPLUG_CPU
2267a7f7f624SMasahiro Yamada	help
2268a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2269a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2270a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2271a71c8bc5SFenghua Yu
2272a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2273a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2274a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2275a71c8bc5SFenghua Yu
2276a71c8bc5SFenghua Yu	  If unsure, say N.
2277a71c8bc5SFenghua Yu
2278506f1d07SSam Ravnborgconfig COMPAT_VDSO
2279b0b49f26SAndy Lutomirski	def_bool n
2280b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2281953fee1dSIngo Molnar	depends on COMPAT_32
2282a7f7f624SMasahiro Yamada	help
2283b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2284b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2285b0b49f26SAndy Lutomirski	  indicated in its segment table.
2286e84446deSRandy Dunlap
2287b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2288b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2289b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2290b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2291b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2292506f1d07SSam Ravnborg
2293b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2294b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2295b0b49f26SAndy Lutomirski
2296b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2297b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2298b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2299b0b49f26SAndy Lutomirski
2300b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2301b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2302506f1d07SSam Ravnborg
23033dc33bd3SKees Cookchoice
23043dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23053dc33bd3SKees Cook	depends on X86_64
2306625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23073dc33bd3SKees Cook	help
23083dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23093dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23103dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23113dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23123dc33bd3SKees Cook
23133dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2314bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23153dc33bd3SKees Cook
23163dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23173dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23183dc33bd3SKees Cook	  to improve security.
23193dc33bd3SKees Cook
2320bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23213dc33bd3SKees Cook
23223dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2323bd49e16eSAndy Lutomirski		bool "Full emulation"
23243dc33bd3SKees Cook		help
2325bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2326bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2327bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2328bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2329bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2330bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2331bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2332bd49e16eSAndy Lutomirski
2333bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2334bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2335bd49e16eSAndy Lutomirski
2336bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2337bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2338bd49e16eSAndy Lutomirski		help
2339bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2340bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2341bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2342bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2343bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2344bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2345bd49e16eSAndy Lutomirski		  buffer.
23463dc33bd3SKees Cook
23473dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23483dc33bd3SKees Cook		bool "None"
23493dc33bd3SKees Cook		help
23503dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23513dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23523dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23533dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23543dc33bd3SKees Cook		  malicious userspace programs can be identified.
23553dc33bd3SKees Cook
23563dc33bd3SKees Cookendchoice
23573dc33bd3SKees Cook
2358516cbf37STim Birdconfig CMDLINE_BOOL
2359516cbf37STim Bird	bool "Built-in kernel command line"
2360a7f7f624SMasahiro Yamada	help
2361516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2362516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2363516cbf37STim Bird	  necessary or convenient to provide some or all of the
2364516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2365516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2366516cbf37STim Bird
2367516cbf37STim Bird	  To compile command line arguments into the kernel,
2368516cbf37STim Bird	  set this option to 'Y', then fill in the
236969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2370516cbf37STim Bird
2371516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2372516cbf37STim Bird	  should leave this option set to 'N'.
2373516cbf37STim Bird
2374516cbf37STim Birdconfig CMDLINE
2375516cbf37STim Bird	string "Built-in kernel command string"
2376516cbf37STim Bird	depends on CMDLINE_BOOL
2377516cbf37STim Bird	default ""
2378a7f7f624SMasahiro Yamada	help
2379516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2380516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2381516cbf37STim Bird	  command line at boot time, it is appended to this string to
2382516cbf37STim Bird	  form the full kernel command line, when the system boots.
2383516cbf37STim Bird
2384516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2385516cbf37STim Bird	  change this behavior.
2386516cbf37STim Bird
2387516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2388516cbf37STim Bird	  by the boot loader) should specify the device for the root
2389516cbf37STim Bird	  file system.
2390516cbf37STim Bird
2391516cbf37STim Birdconfig CMDLINE_OVERRIDE
2392516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2393645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2394a7f7f624SMasahiro Yamada	help
2395516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2396516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2397516cbf37STim Bird
2398516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2399516cbf37STim Bird	  be set to 'N' under normal conditions.
2400516cbf37STim Bird
2401a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2402a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2403a5b9e5a2SAndy Lutomirski	default y
2404a7f7f624SMasahiro Yamada	help
2405a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2406a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2407a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2408a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2409a5b9e5a2SAndy Lutomirski	  threading libraries.
2410a5b9e5a2SAndy Lutomirski
2411a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2412a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2413a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2414a5b9e5a2SAndy Lutomirski
2415a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2416a5b9e5a2SAndy Lutomirski
2417b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2418b700e7f0SSeth Jennings
2419506f1d07SSam Ravnborgendmenu
2420506f1d07SSam Ravnborg
24213072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24223072e413SMichal Hocko	def_bool y
24233072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24243072e413SMichal Hocko
2425506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2426506f1d07SSam Ravnborg	def_bool y
2427506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2428506f1d07SSam Ravnborg
242935551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
243035551053SGary Hade	def_bool y
243135551053SGary Hade	depends on MEMORY_HOTPLUG
243235551053SGary Hade
2433e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2434645a7919STejun Heo	def_bool y
2435e534c7c5SLee Schermerhorn	depends on NUMA
2436e534c7c5SLee Schermerhorn
24379491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24389491846fSKirill A. Shutemov	def_bool y
24399491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24409491846fSKirill A. Shutemov
2441c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2442c177c81eSNaoya Horiguchi	def_bool y
2443c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2444c177c81eSNaoya Horiguchi
24459c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24469c670ea3SNaoya Horiguchi	def_bool y
24479c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24489c670ea3SNaoya Horiguchi
2449da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2450e279b6c1SSam Ravnborg
2451e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24523c2362e6SHarvey Harrison	def_bool y
245344556530SZhimin Gu	depends on HIBERNATION
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2456e279b6c1SSam Ravnborg
2457e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2458e279b6c1SSam Ravnborg
2459a6b68076SAndi Kleenconfig X86_APM_BOOT
24606fc108a0SJan Beulich	def_bool y
2461282e5aabSPaul Bolle	depends on APM
2462a6b68076SAndi Kleen
2463e279b6c1SSam Ravnborgmenuconfig APM
2464e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2465efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2466a7f7f624SMasahiro Yamada	help
2467e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2468e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2469e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2470e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2471e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2472e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2473e279b6c1SSam Ravnborg
2474e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2475e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2476e279b6c1SSam Ravnborg
2477e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2478e279b6c1SSam Ravnborg	  machines with more than one CPU.
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2481151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24822dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2483e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2486e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2487e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2490e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2491e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2492e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2495e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2496e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2497e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2498e279b6c1SSam Ravnborg	  APM in your BIOS).
2499e279b6c1SSam Ravnborg
2500e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2501e279b6c1SSam Ravnborg	  "weird" problems:
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2504e279b6c1SSam Ravnborg	  enabled.
2505e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2506e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2507e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2508e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2509e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2510e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2511e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2512e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2513e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2514e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2515e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2516e279b6c1SSam Ravnborg	  11) exchange RAM chips
2517e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2518e279b6c1SSam Ravnborg
2519e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2520e279b6c1SSam Ravnborg	  module will be called apm.
2521e279b6c1SSam Ravnborg
2522e279b6c1SSam Ravnborgif APM
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2525e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2526a7f7f624SMasahiro Yamada	help
2527e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2528e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2529e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2530e279b6c1SSam Ravnborg
2531e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2532e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2533a7f7f624SMasahiro Yamada	help
2534e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2535e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2536e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2537e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2538e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2539e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2540e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2541e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2542e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2543e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2544e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2545e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2546e279b6c1SSam Ravnborg	  this feature.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2549dd8af076SLen Brown	depends on CPU_IDLE
2550e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2551a7f7f624SMasahiro Yamada	help
2552e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2553e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2554e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2555e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2556e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2557e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2558e279b6c1SSam Ravnborg	  this option does nothing.)
2559e279b6c1SSam Ravnborg
2560e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2561e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2562a7f7f624SMasahiro Yamada	help
2563e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2564e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2565e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2566e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2567e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2568e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2569e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2570e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2571e279b6c1SSam Ravnborg	  especially if you are using gpm.
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2574e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2575a7f7f624SMasahiro Yamada	help
2576e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2577e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2578e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2579e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2580e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2581e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborgendif # APM
2584e279b6c1SSam Ravnborg
2585bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2588e279b6c1SSam Ravnborg
258927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
259027471fdbSAndy Henroid
2591e279b6c1SSam Ravnborgendmenu
2592e279b6c1SSam Ravnborg
2593e279b6c1SSam Ravnborg
2594e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2595e279b6c1SSam Ravnborg
2596e279b6c1SSam Ravnborgchoice
2597e279b6c1SSam Ravnborg	prompt "PCI access mode"
2598efefa6f6SIngo Molnar	depends on X86_32 && PCI
2599e279b6c1SSam Ravnborg	default PCI_GOANY
2600a7f7f624SMasahiro Yamada	help
2601e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2602e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2603e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2604e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2605e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2608e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2609e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2610e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2611e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2612e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2613e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2614e279b6c1SSam Ravnborg
2615e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2616e279b6c1SSam Ravnborg	bool "BIOS"
2617e279b6c1SSam Ravnborg
2618e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2619e279b6c1SSam Ravnborg	bool "MMConfig"
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2622e279b6c1SSam Ravnborg	bool "Direct"
2623e279b6c1SSam Ravnborg
26243ef0e1f8SAndres Salomonconfig PCI_GOOLPC
262576fb6570SDaniel Drake	bool "OLPC XO-1"
26263ef0e1f8SAndres Salomon	depends on OLPC
26273ef0e1f8SAndres Salomon
26282bdd1b03SAndres Salomonconfig PCI_GOANY
26292bdd1b03SAndres Salomon	bool "Any"
26302bdd1b03SAndres Salomon
2631e279b6c1SSam Ravnborgendchoice
2632e279b6c1SSam Ravnborg
2633e279b6c1SSam Ravnborgconfig PCI_BIOS
26343c2362e6SHarvey Harrison	def_bool y
2635efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2636e279b6c1SSam Ravnborg
2637e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2638e279b6c1SSam Ravnborgconfig PCI_DIRECT
26393c2362e6SHarvey Harrison	def_bool y
26400aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2641e279b6c1SSam Ravnborg
2642e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2643b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2644b45c9f36SJan Kiszka	default y
2645*4590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2646b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2647e279b6c1SSam Ravnborg
26483ef0e1f8SAndres Salomonconfig PCI_OLPC
26492bdd1b03SAndres Salomon	def_bool y
26502bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26513ef0e1f8SAndres Salomon
2652b5401a96SAlex Nixonconfig PCI_XEN
2653b5401a96SAlex Nixon	def_bool y
2654b5401a96SAlex Nixon	depends on PCI && XEN
2655b5401a96SAlex Nixon	select SWIOTLB_XEN
2656b5401a96SAlex Nixon
26578364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26588364e1f8SJan Kiszka	def_bool y
26598364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2660e279b6c1SSam Ravnborg
26613f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26626a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26636ea30386SKees Cook	depends on PCI
26643f6ea84aSIra W. Snyder	help
26653f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26663f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26673f6ea84aSIra W. Snyder	  not have ACPI.
26683f6ea84aSIra W. Snyder
266964a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
267064a5fed6SBjorn Helgaas	  is known to be incomplete.
267164a5fed6SBjorn Helgaas
267264a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
267364a5fed6SBjorn Helgaas
26743a495511SWilliam Breathitt Grayconfig ISA_BUS
267517a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26763a495511SWilliam Breathitt Gray	help
267717a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
267817a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
267917a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
268017a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
268117a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26823a495511SWilliam Breathitt Gray
26833a495511SWilliam Breathitt Gray	  If unsure, say N.
26843a495511SWilliam Breathitt Gray
26851c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2686e279b6c1SSam Ravnborgconfig ISA_DMA_API
26871c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26881c00f016SDavid Rientjes	default y
26891c00f016SDavid Rientjes	help
26901c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26911c00f016SDavid Rientjes	  If unsure, say Y.
2692e279b6c1SSam Ravnborg
269351e68d05SLinus Torvaldsif X86_32
269451e68d05SLinus Torvalds
2695e279b6c1SSam Ravnborgconfig ISA
2696e279b6c1SSam Ravnborg	bool "ISA support"
2697a7f7f624SMasahiro Yamada	help
2698e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2699e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2700e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2701e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2702e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2703e279b6c1SSam Ravnborg
2704e279b6c1SSam Ravnborgconfig SCx200
2705e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2706a7f7f624SMasahiro Yamada	help
2707e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2708e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2709e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2710e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2711e279b6c1SSam Ravnborg
2712e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2713e279b6c1SSam Ravnborg
2714e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2715e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2716592913ecSJohn Stultz	depends on SCx200
2717e279b6c1SSam Ravnborg	default y
2718a7f7f624SMasahiro Yamada	help
2719e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2720e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2721e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2722e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2723e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2724e279b6c1SSam Ravnborg
27253ef0e1f8SAndres Salomonconfig OLPC
27263ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
272754008979SThomas Gleixner	depends on !X86_PAE
27283c554946SAndres Salomon	select GPIOLIB
2729dc3119e7SThomas Gleixner	select OF
273045bb1674SDaniel Drake	select OF_PROMTREE
2731b4e51854SGrant Likely	select IRQ_DOMAIN
27320c3d931bSLubomir Rintel	select OLPC_EC
2733a7f7f624SMasahiro Yamada	help
27343ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27353ef0e1f8SAndres Salomon	  XO hardware.
27363ef0e1f8SAndres Salomon
2737a3128588SDaniel Drakeconfig OLPC_XO1_PM
2738a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2739fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2740a7f7f624SMasahiro Yamada	help
274197c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2742bf1ebf00SDaniel Drake
2743cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2744cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2745cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2746a7f7f624SMasahiro Yamada	help
2747cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2748cfee9597SDaniel Drake	  programmable wakeup source.
2749cfee9597SDaniel Drake
27507feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27517feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
275292e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2753ed8e47feSRandy Dunlap	depends on INPUT=y
2754d8d01a63SDaniel Drake	select POWER_SUPPLY
2755a7f7f624SMasahiro Yamada	help
27567feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27577bc74b3dSDaniel Drake	   - EC-driven system wakeups
27587feda8e9SDaniel Drake	   - Power button
27597bc74b3dSDaniel Drake	   - Ebook switch
27602cf2baeaSDaniel Drake	   - Lid switch
2761e1040ac6SDaniel Drake	   - AC adapter status updates
2762e1040ac6SDaniel Drake	   - Battery status updates
27637feda8e9SDaniel Drake
2764a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2765a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2766d8d01a63SDaniel Drake	depends on OLPC && ACPI
2767d8d01a63SDaniel Drake	select POWER_SUPPLY
2768a7f7f624SMasahiro Yamada	help
2769a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2770a0f30f59SDaniel Drake	   - EC-driven system wakeups
2771a0f30f59SDaniel Drake	   - AC adapter status updates
2772a0f30f59SDaniel Drake	   - Battery status updates
2773e279b6c1SSam Ravnborg
2774d4f3e350SEd Wildgooseconfig ALIX
2775d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2776d4f3e350SEd Wildgoose	select GPIOLIB
2777a7f7f624SMasahiro Yamada	help
2778d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2779d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2780d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2781d4f3e350SEd Wildgoose	  get added here.
2782d4f3e350SEd Wildgoose
2783d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2784d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2785d4f3e350SEd Wildgoose
2786d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2787d4f3e350SEd Wildgoose
2788da4e3302SPhilip Prindevilleconfig NET5501
2789da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2790da4e3302SPhilip Prindeville	select GPIOLIB
2791a7f7f624SMasahiro Yamada	help
2792da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2793da4e3302SPhilip Prindeville
27943197059aSPhilip A. Prindevilleconfig GEOS
27953197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27963197059aSPhilip A. Prindeville	select GPIOLIB
27973197059aSPhilip A. Prindeville	depends on DMI
2798a7f7f624SMasahiro Yamada	help
27993197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28003197059aSPhilip A. Prindeville
28017d029125SVivien Didelotconfig TS5500
28027d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28037d029125SVivien Didelot	depends on MELAN
28047d029125SVivien Didelot	select CHECK_SIGNATURE
28057d029125SVivien Didelot	select NEW_LEDS
28067d029125SVivien Didelot	select LEDS_CLASS
2807a7f7f624SMasahiro Yamada	help
28087d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28097d029125SVivien Didelot
2810e279b6c1SSam Ravnborgendif # X86_32
2811e279b6c1SSam Ravnborg
281223ac4ae8SAndreas Herrmannconfig AMD_NB
2813e279b6c1SSam Ravnborg	def_bool y
28140e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2815e279b6c1SSam Ravnborg
2816e3263ab3SDavid Herrmannconfig X86_SYSFB
2817e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2818e3263ab3SDavid Herrmann	help
2819e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2820e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2821e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2822e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2823e3263ab3SDavid Herrmann	  to x86.
2824e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2825e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2826e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2827e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2828e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2829e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2830e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2831e3263ab3SDavid Herrmann
2832e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2833e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2834e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2835e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2836e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2837e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2838e3263ab3SDavid Herrmann	  incompatible with simplefb.
2839e3263ab3SDavid Herrmann
2840e3263ab3SDavid Herrmann	  If unsure, say Y.
2841e3263ab3SDavid Herrmann
2842e279b6c1SSam Ravnborgendmenu
2843e279b6c1SSam Ravnborg
2844e279b6c1SSam Ravnborg
28451572497cSChristoph Hellwigmenu "Binary Emulations"
2846e279b6c1SSam Ravnborg
2847e279b6c1SSam Ravnborgconfig IA32_EMULATION
2848e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2849e279b6c1SSam Ravnborg	depends on X86_64
285039f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2851d1603990SRandy Dunlap	select BINFMT_ELF
2852a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
285339f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2854a7f7f624SMasahiro Yamada	help
28555fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28565fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28575fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2858e279b6c1SSam Ravnborg
2859e279b6c1SSam Ravnborgconfig IA32_AOUT
2860e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28616b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2862eac61655SBorislav Petkov	depends on BROKEN
2863a7f7f624SMasahiro Yamada	help
2864e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2865e279b6c1SSam Ravnborg
28660bf62763SH. Peter Anvinconfig X86_X32
28676ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28689b54050bSBrian Gerst	depends on X86_64
2869a7f7f624SMasahiro Yamada	help
28705fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28715fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28725fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28735fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28745fd92e65SH. J. Lu
28755fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28765fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28775fd92e65SH. J. Lu	  option set.
28785fd92e65SH. J. Lu
2879953fee1dSIngo Molnarconfig COMPAT_32
2880953fee1dSIngo Molnar	def_bool y
2881953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2882953fee1dSIngo Molnar	select HAVE_UID16
2883953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2884953fee1dSIngo Molnar
2885e279b6c1SSam Ravnborgconfig COMPAT
28863c2362e6SHarvey Harrison	def_bool y
28870bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2888e279b6c1SSam Ravnborg
28893120e25eSJan Beulichif COMPAT
2890e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28913120e25eSJan Beulich	def_bool y
2892e279b6c1SSam Ravnborg
2893e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28943c2362e6SHarvey Harrison	def_bool y
28953120e25eSJan Beulich	depends on SYSVIPC
28963120e25eSJan Beulichendif
2897ee009e4aSDavid Howells
2898e279b6c1SSam Ravnborgendmenu
2899e279b6c1SSam Ravnborg
2900e279b6c1SSam Ravnborg
2901e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2902e5beae16SKeith Packard	def_bool y
2903e5beae16SKeith Packard	depends on X86_32
2904e5beae16SKeith Packard
2905e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2906e279b6c1SSam Ravnborg
2907edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29085e8ebd84SJason A. Donenfeld
29095e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2910